1. Field of the Invention
The present invention relates to a microlens array, a light intensity distribution uniformizing element having the same, and a projection apparatus including the light intensity distribution uniformizing element.
2. Description of the Related Art
Microlens arrays in which a large number of microlenses are arranged one-dimensionally or two dimensionally are known. For example, Japanese Patent Application Laid-Open No. 6-250002 discloses a method of manufacturing such microlens arrays. More specifically, a method of manufacturing microlens arrays by using optical patterning and dry etching is disclosed. With the microlenses, a light intensity distribution uniformizing element that uniformizes light intensity distribution can be formed, for example.
In formation of a microlens array with glass, for example, it is difficult to form the entire surfaces of microlenses constituting the microlens array into an ideal lens shape owing to the required processing accuracy. In particular, it is difficult to form an ideal lens shape around boundaries between adjacent microlenses. Portions that are not in the ideal lens shape are ineffective portions that do not function as desirable lenses. The presence of the ineffective portions causes optical loss. The optical loss is greater as the ineffective portions are larger.
Use of resin, for example, facilitates more accurate formation of microlens arrays than using glass. Resin, however, is more susceptible to thermal degradation than glass, for example.
An object of the present invention is to provide a microlens array with reduced optical loss and less susceptible to degradation, a light intensity distribution uniformizing element having the same, and a projection apparatus including the light intensity distribution uniformizing element.